Feeding mechanism for sewing machines



y 7, 1940- H. HACKLANDER AL 2.199.663

FEEDING MECHANISM FOR SEWING MACHINES Filed June 22, 195'? 3 Sheets-Sheet 1 INVENTORS: i'fans fiacirlander 25 y George Sam; I

May 7, 1940- H. HACKLANDER ET AL FEEDING MECHANISM FOR SEWING MACHINES a Sheets-Sheet 2 Filed June 22, 1937 INVENTORS Hams fiacklander 15 a Samar I I NM w mm N mm mm Georg 7% May 7, 1940. H. HACKLANDER El AL FEEDING MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 5 Filed June22, 1937 INVENTOR s ifims ifuirlander 15 y George Samar ATTORNEY Patented May 7, 1940 UNITED STATES PATENT, OFFICE MAC Hans Hacklander, Linden,

N. 1., and George Sauer, Berwyn, Ill., assignors to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application June 22, 1937, Serial No. 149,593

8 Claims.

This invention relates to feeding mechanism for sewing machines, and it has reference more especially to feeding mechanism for sewing machines of the feed-oif-the-arm type.

a In sewing machines of the kind specifically referred to, the carrier bar for the feed dog is ordinarily actuated through relatively long link members which are in endwise compression incident to impartation of the rising movements to lo the bar at the times when the feed dog opposes the downward pressure of the presser foot. Accordingly these link members must be of heavy construction so as to be capable of resisting lateral flexure under endwise compression, and

15 as a consequence of their momentum have restraining influence upon the speed of the sewing machine.

The purpose of our invention is to overcome the drawback to which attention has just been directed, that is to say, it has for its aim to make possible the use of much lighter link members in feeding mechanism so that higher speeds may be attained in the operation of the sewing machines and a correspondingly greater output secured from them. This advantage we realize as hereinafter more fully disclosed, through. provision of improved actuating means for the feed dog whereby the rising movements are induced through pull or tension upon the link members.

30 The link members can be thus made very light in weight since they are not obliged to oppose lateral bending strains as in the usual forms of feeding mechanisms.

In the attached drawings, Fig. I is a side eleva- 35 tion of a feed-ofi-the-arm sewing machine embodying our invention in a form which gives excellent results in practice, a portion of the machine frame being broken out for exposure of important parts of the mechanism at the interior.

Fig. 11 is a longitudinal sectional view of the arm-like work support of the machine.

Fig. III is a. view partly in planand partly in section taken as indicated by the arrows III-lII in Figs. I and 11 with the cover plates removed from the work support.

Figs. IV, V, VI, VII, and VIII are cross sectional views taken as indicated respectively by the arrows IV-IV, V-V, VI-VI, VII-VII, and VIII-VIII in Figs. II and III; and

Fig. IX is a perspective view of a bell crank member constituting one of the elements by which the rising and falling movements are imparted to the feed dog carrier or feed bar of the I machine.

(Cl. 112-2l5) The feed-oiI-the-arm sewing machine chosen for convenience of illustrating our invention herein is generally of the type disclosed in U. S. Patent No. 1,741,095, granted to Norman V. Christensen and Harold J. Le Vesconte on De- 6 cember 24, 1929, the same having a hollow armlike work support I whereof the free end underreaches a needle head 2 at the corresponding end of an elevated horizontal tubular portion 3 integrally formed with a bracket-like supporting lt base 4. The drive shaft 5 of the machine is suitably journaled within the hollow of the elevated frame portion 3 and is provided at one end with a. combined hand wheel and pulley 6 so that it may be operated either manually or by power. The needle bar indicated at 1 and carrying the needles 8 is guided for vertical movement in the'head 2 and arranged to be actuated by suitable connections (not illustrated) from the drive shaft 5. The presser bar 9 of the machine is likewise confined to up and down movement in the head 2, and, as usual carries a presser foot Ill at its lower end. By means of a stifi leaf spring whereof the front end is indicated at H in Fig. I and shown as being engaged with the top end of the presser bar 9, the presser foot I0 is yieldingly maintained in contact with the material (not illustrated)- which is to be sewed. Arranged to cooperate with the needles 8 in forming chain stitch seams is a looper I2, which, see Fig. II, is mounted on the front end of a horizontal shaft l3 supported with capacity for oscillation as well as for longitudinal shifting movement in bearings l4 and I5 within the hollow of the work support I. Rocking movements are imparted to the looper shaft I3 through a strap rod Hi from a rotary eccentric actuator I! on the drive shaft 5 of the machine, said rod extending downwardly through the hollow vertical portion l8 of the machine frame which joins the work support I with the elevated portion 3, and being pivotally connected at its lower end to an arm I!) on said shaft. Endwise movements are induced in the looper shaft l3 by another rotating eccentric actuator 20 on the main shaft 5. As shown, the strap rod 2| of the eccentric actuator 20, like the strap rod l6, extends down through the hollow vertical portion of the machine frame and has its lower end pivotally connected to the horizontal arm 22 of a bell crank member 23 (Fig. III) fulcrumed on a cross pin 24 in the rear part of the work support I, the other arm 25 (Figs. II and VIII) of said bell crank member being coupled, by means of a short link 26, with a collar 2'! rotatively free on the u looper shaft i3 between the arm i9 and a fixed collar 28. Operatively associated with the looper i2 is a spreader 29, which (see Fig. II) is secured on the front end of a sleeve which provides the front bearing i4 for the looper shaft l3, and which is in turn journaled in a bushing 3i set into a web or partition 32, extending crosswise of the hollow of the work supporting arm i. Near its rear end, the sleeve 30 is journaledin a bearing lug 33 at an intermediate point within the work support I. Another eccentric actuator 34 on the drive shaft 5 whereof the strap rod 35 extends down through the hollow vertical portion of the machine frame and is connected at its lower end to a ball arm 36 on the rear end of the sleeve 30 serves to rock said sleeve with resultant impartation of lateral oscillatory movements to the spreader 29. The complemental stitch-forming mechanism just described constitutes the subject matter of a separate patent application No. 149,592 filed by us "concurrently herewith.

Having now generally set forth the characteristics of a sewing machine in connection with which the feeding mechanism of our invention is advantageously employable, we will now proceed to describe said mechanism indetail. Bridging an opening at the front end of a feed bar 31 extending longitudinally of the hollow .of the work support I and secured to said bar by screws 38, is a feed dog 39. Adjacent the feed dog 39, the feed bar 31 has sliding guidance in a longitudinal slot 40 in the upper part of the partition 32 extending crosswise of the work support I. Immediately rearward of the partition 32 the feed bar 31 is supported at the upper ends of a pair of upright links 4|, which, at their lower ends are pivotally connected to the forwardly reaching horizontal arm 42 of a bell crank member 43 (Figs. II, V and IX) which is free to oscillate about the eccentric medial portion 44 of a transverse pin 45 (Fig. VI) held in place in bosses 46 interiorly of the work support i by a screw 41. Rising and falling movements are imparted to the feed dog 39 through a horizontal link 48 whereof the front end is connected to the upstanding arm 49 of the bell crank member 43 and the rear end to the pendant arm 50 of another bell crank member 5| mounted to oscillate on a cross pin 52 in the rear portion of the work support. The rearwardly-extending horizontal arm 53 of the bell crank lever 5| is in turn connected to the lower end of a straprod 54 of another rotary eccentric actuator 55 on the drive shaft 5 of the machine, said strap rod extending with the others down through the verti-' cal hollow portion of the machine frame.

Back and forth or feeding movements are induced in the feed bar 31 by means which includes another rotary eccentric actuator 56 on the drive shaft 5. As shown in Fig. III, the downwardly extending strap rod 51 of this eccentric actuator 56 within the vertical tubular portion of the frame is connected to the ball end of a stud 58 adjustable along a slot 59 in the horizontal forwardly-projecting arm 50 of a bell crank lever 6| which is freely fulcrumed on the cross pin 24 hereinbefore referred to, the pendant arm 62 of said lever being pivotally connectedto the rear end of the feed bar 31 at 63. By adjusting the stud 58 along the slotted arm 69 of the bell crank member 6|, it is evident that the swing of the latter under the influence of the rotary actuator 56 will be varied and the back and forth or the feed stroke of the feed dog 39 correspondingly increased or decreased as desired or required. Since the slotted arm 80 of the bell crank member 5| is horizontal and substantially parallel with the drive shaft 5, the adjustment of the stud 58 as above will not appreciably change the timing of the feed stroke of the feed dog and therefore-not interfere with the proper operation of the feeding mechanism. Access is had to the stud 58 for the purpose of adjustment upon removal of a screw plug 64 closing an opening in one side of the work support I, see Fig. 111. When it is desired to change the path of backand forth travel of the feed dog 39 relative to the slots in the throat plate of the machine indicated at 59 in Figs. I and II, this may be accomplished by rotative adjustment of the strap rod 54, which, as shown, is provided at its upper and lower ends with oppositely pitched screw threads for this purpose. By rotatively adjusting the fulcrum pin 45 of the bell crank lever 43, it is possible, on the other hand, to vertically shift the up and down path of the feed dog 39.

It is to be particularly noted that under the action of the rotary eccentric actuator 55, the

strap rod 54 and the link 48 are both subjected bending strains as in the usual forms of feeding mechanisms, to the end that said parts can be made much lighter in weight with attendant decrease proportionately of their momentum and the vibration due thereto. Thus, a sewing machine embodying our. improved feeding mechanism can be operated at higher speeds than those having the ordinary forms of feeding mechanisms, and a correspondingly higher output secured from them.

Having thus described our invention, we claim:

1. Feeding mechanism for sewing machines comprising a feed dog and a horizontal carrier therefor; means for imparting back and forth or feeding movements to the carrier; and means for imparting rising and falling movements to the carrier, including a horizontal link member extending rearward of the carrier in respect to the direction of. feeding, and an actuator which induces the rising movements of the feed dog carrier by endwise pull upon said link member.

2. Feeding mechanism for sewing machines comprising a feed dog and a horizontal carrier therefor; means for imparting back and forth or feeding movements to the carrier: and means for imparting rising and falling movements to the carrier including a horizontal link member extending rearward of the carrier in respect to the direction of feeding, a shaft with a rotary eccentric actuator thereon, and interposed means whereby the rotary actuator effects therising' movements of the feed dog carrier through endwise pull upon said link member.

3. Feeding mechanism for sewing machines comprising a feed dog and a horizontal carrier therefor; means for imparting back and forth or feeding movements to the carrier; and means for imparting rising and falling movements to the carrier including a horizontal link member extending rearward of the carrier in respect tofeed bar 2,199,663 are induced from the rotary actuator through endwise pull on both the link and the strap rod.

4. Feeding mechanism for feed-ofi-the-arm sewing machines wherein a hollow arm-like work support is joined at one end by a tubular vertical connecting portion to an elevated tubular horizontal portion of the machine frame, and wherein a drive shaft extends lengthwise of the elevated portion, said feeding mechanism including a longitudinal feed bar within the hollow of. the work support; a feed dog at. the front end of the bar; a vertical link to the top end of which the feed bar is connected near its front end, a bell crank lever with a forwardly projecting horizontal arm to which the lower end of the vertical link is connected, a horizontal link member connected to an upright arm of the bell crank lever and extending rearwardly of the work support, a rotary eccentric actuator on the drive shaft, and connections extending down through the vertical portion of the machine frame whereby the rising movements are induced in the feed bar through pull upon the horizontal link.

5. Feeding mechanism for feed-ofi-the-arm sewing machines wherein a hollow arm-like work support is joined at one end by a tubular vertical connecting portion to a horizontal elevated portion of the machine frame, and wherein a drive shaft'extends lengthwise of the elevated portion, said feeding mechanism including a longitudinal feed bar within the hollow of. the work support; a feed dog on the front end of the bar; means actuated from the drive shaft for imparting back and forth or feeding movements to the feed bar; and means for imparting rise and fall movements to the feed bar including a rotary eccentric actuator on the drive shaft, a bell crank lever within the work support having a rearwardly extending horizontal arm; a strap rod extending down from the rotary eccentric actuator through the vertical portion of the machine frame and connected to the horizontal arm of the lever, a vertical link to the top end of which the feed bar is connected near its front end, another bell crank lever within the work support having a forwardly projecting horizontal arm whereto the lower end of. the vertical link is connected; and a horizontal link connecting an upright arm of the last mentioned bell crank lever with a pendant arm of the first mentioned bell crank lever.

6. Feeding mechanism sewing machines wherein a hollow arm-like work support is joined at one end through a. tubular vertical connecting portion to a horizontal tubular elevated portion of the machine frame, and wherein a drive shaft extends lengthwise of the elevated portion, said feeding mechanism includfor feed-off-the-arm ing a longitudinal feed bar within the hollow of the work support; a feed dog at the front end of the bar; means for imparting back and forth or feeding movements to the feed bar including a rotary eccentric actuator on the drive shaft having a strap rod extending downwardly therefrom through the vertical tubular portion ofthe machine frame into the work support, and a bell crank lever within the work support having a forwardly projecting arm whereto the strap rod is connected at its lower end and a pendant arm to which the feed bar is connected at its rear end; and means for imparting rising and falling movements to the feed bar including a vertical link to the top end of which the feed bar is connected near its front end, a second bell crank lever within the work support having a forwardly projecting horizontal arm to which the lower end of the vertical link is connected, another rotary eccentric actuator on the "ve shaft having a strap rod extending down through the vertical frame portion into the work support, a third bell crank lever within the work support having a rearwardly projecting horizontal arm connected to the lower end of the last mentioned strap rod, and a horizontal link connecting an upright arm of the second bell crank lever with a pendant arm of the third bell crank lever.

7. In a sewing machine having a hollow work supporting arm, feeding mechanism within said arm including a bar which extends longitudinally of-the arm and which has a feed dog at its front end, means intermediate the ends of the bar supporting it with capacity to respond to endwise or feeding movements and including a rocker, means for actuating the rocker to impart rising and falling movements to the bar, and means connected to the rear end of the bar for imparting endwise or feeding movements thereto.

8. In a sewing machine having a hollow work supporting arm, and looper mechanism within the arm including a shaft which extends longitudinally of the bottom of the arm; feeding mechanism also within the which extends longitudinally of the arm and which has a feed dog at its'front end, means intermediate the ends of the bar supporting it with capacity to respond to endwise or feeding movements and including a rocker with its fulcrum above the'looper shaft, means for actuating the rocker to impart rising and falling movements to the bar, and means connected to the rear end of the bar for imparting endwise or feeding movements thereto.

HANS HACUAANDER. GEORGE BAUER.

arm including a bar 

